In externally powered machine guns, the energy for driving the weapon is not obtained from gas pressure or from weapon recoil, but is provided by an electrical or hydraulic drive. Particularly in the case of electrically driven weapons, the rotary movement of the motor must, for this purpose, be converted to an oscillating movement of the breech. Furthermore, the breech requires times for which it is stationary at the limit positions of its displacement movement. In a first limit position, the case of the previous round must be removed in front of the breech, and a new cartridge must be fed in front of the breech before the cartridge is driven into the cartridge chamber of the weapon barrel. In a further limit position, the breech must be locked and the cartridge fired. Once the gas pressure in the weapon barrel has fallen, the breech can then be unlocked.
A rigidly locked linear breech for an externally driven machine gun has been published in DE 36 27 361 C1. A control roll is also proposed here, for space-saving locking, without bouncing.
DE 37 12 905 A1 describes a machine gun which, inter alia, has a cam drum that is operated by an external drive and is used for linear movement of a linear breech. The cam drum correspondingly has a control cam, which runs endlessly over the circumference. Furthermore, a short radially acting control cam and a longer axially acting control cam are arranged on the circumference.
DE 10 2005 045 824 A1 proposes a physically small weapon whose control roll is integrated on the plane of the barrel bore axis. The control roll has a control body to which at least two control cams are fitted. In this case, the cam information is converted to a linear feed of the breech.
From DE 10 2007 048 468.4, which was not published prior to the priority date of this application, a drive is preferred for linear feeding of a breech, or of the ammunition into a weapon barrel, or a cartridge camber by means of a chain. In contrast to the bushmaster drive, in which a chain is passed over four sprocket wheels, in the form of a rectangle, and by means of which the stationary times of the breech are defined, the chain is, in this case, itself passed tightly around two sprocket wheels in a simple manner. A chain link or a stud on the chain is integrated in a guide or groove that is located under the movable slide. This allows the chain to continue to run during the times when the weapon is stationary, which are defined by a separate function control means. The chain itself can be driven by an electric motor. A rapid stopping means is, in this case, integrated in the path of the chain.
A linear feed of a breech with respect to the weapon barrel or cartridge chamber is described in DE 10 2007 054 470.9, which was not published prior to the priority date of this application. In this case, a linear guide groove is integrated in the drive kinematics. A means, which is physically connected to the breech, is guided in the guide groove. The guide groove is itself surrounded by a circumferential positive guide (slotted link), which itself interprets the necessary times for the breech to be stationary during locking, firing and unlocking in its front position and during loading, once the breech has been moved to its rear position. A further means is guided within the positive guide, as drive means for the breech. The drive transmission can be provided by sliding rollers, gear wheels, or the like, which are driven by a motor, etc. The drive itself continues to run during the times in which the weapon is stationary, while the breech is moved out and back in again later during the stationary times.
Although the three last-mentioned solutions themselves already deal with practicable drives, which produce satisfactory results in terms of firing rate and mechanical wear, the invention is based on the object of specifying a further drive for a breech, such as this, which is likewise also used for higher firing rates.